• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.549-555
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• 2018

The medical imaging technique images the contrast formed based on the difference in absorption coefficient of X-rays which changes according to the composition and thickness of the object. At this time, not only primary rays entering the image detector but also scattered rays greatly affect the image quality. Therefore, in this paper, Forward scattering rate and Scattered to primary ratio analysis were performed through Monte Carlo simulation in order to consider influence of scattered ray generated according to object thickness and radiation exposure area change on image quality. In the study, the Forward scattering rate corresponding to the thickness of the object was analyzed at a maximum of 15.3%p and the Scattered to primary ratio was analyzed at 2.00 to 4.54, but it was analyzed as maintaining a constant value for radiation exposure area change. Based on these results, the thickness of the object should be considered as a factor influencing the quality of the image, but radiation exposure area verified that it is a factor that does not affect the image quality. We believe that the results of this research can be utilized as basic information of scattered radiation to improve image quality.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.8.1-8.5
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• 2013

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients' 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean government's efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.

• Journal of radiological science and technology
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• v.5 no.1
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• pp.21-34
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• 1982

When unattenuated x-ray radiation passes through the object it is transmitted and scattered from objectes and impinging on the film. During this process certain radiation is absorbed within the object and others transmitted in reduced scattering. The scattering radiation influence upon radiation image quality, confining x-ray beam which means scattering radiation produce increased fog on x-ray film image and as a consequence decrease contrast and less detail of the film there for the elimination of fog and for absorbing scattered radiation, the grid has been used between the object and the film in order to rid of scattering rays. Using grid is good method for the qualification of the better image as well as in using air gap technique. The grid is easy to manipulate and promote good efficiency which is defined by ICRU and JIS. It is the purpose to study for eliminating scattered radiation from the tissue equivalent acryl phantom using grid, we have studied and evaluated the grid permeability about the x-ray exposure, the selection of grid ratio according to phantom thickness, on x-ray exposure are performed as follows. 1. The penetrating ratio of primary x-ray is remarkably decreased by increasing of the grid ratio, but it is almost not influenced in KVP difference and phantom thickness. 2. The scattered radiation is proportionaly increased by thickness of the phantom, having nothing to do with grid ratios. 3. The relative between the penetration rate of primary and secondary x-ray is improved by increasing grid ratio, and decreased by phantom thickness, and slightly decreased by high tube voltage. 4. The grid of 5:1 and 10:1 ratio are adequate to the phantom of 10cm and 15cm thickness, respectively.

• Journal of Environmental Health Sciences
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• v.41 no.3
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• pp.147-162
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• 2015

Objectives: The objective of this review was to summarize the primary role of three representative endocrine axes in aquatic vertebrates and discuss the effects on endocrine systems and their interactions in teleost fish after exposure to environmental contaminants. Methods: We summarized individual traits and mechanisms for hormonal and transcriptional interactions between the hypothalamic-pituitary-gonad (HPG), hypothalamic-pituitary-thyroid (HPT), and hypothalamic-pituitary-adrenal (HPA) axes in fish. We also provided a brief discussion on the effects of nonylphenol-induced toxicity on endocrine systems and their interactions in fish as a demonstration of holistic explanation. Results: Currently-available data showed that thyroid dysfunction is associated with reproductive toxicity due to changes in steroidogenic gene expressions and sex hormone levels as well as gonad glands in fish. As an example, we demonstrated that exposure to nonylphenol could induce estrogenicity in male fish by decreasing thyroid hormones, which contributes to increased aromatase expression. Although the mechanisms are complicated and involved in multiple ways, a number of studies have shown that sex steroids influence the HPT axis or the HPA axis in fish, indicating bi-directional crosstalk. Critically missing is information on the primary target or toxicity mechanisms of environmental contaminants among the three endocrine axes, so further studies are needed to explore those possibilities. Conclusions: This review highlights the interactions between the HPG, HPT, and HPA axes in fish in order to better understand how these endocrine systems could interact with each other in situations of exposure to endocrine disrupting chemicals.

• Journal of the Korean Society of Costume
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• v.51 no.1
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• pp.163-174
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• 2001

The purpose of this study is to review the features of eroticism expressed in men's fashion, to explain psychological and social contexts which engender eroticism and to analyze in what way eroticism is portrayed in men s fashion in this context. Eroticism as the metonymy of forbidden sexual desire, has been embodied mostly in visual forms such as picture and photo. From a psychoanalytic view, the context in which eroticism is formed can be explained by primary narcissism and fetishism. Primary narcissism is the feeling of satisfaction with the self in which the subject who is admiring and the object of admiration are one and the same. Accordingly, in order to give rise to eroticism, both subject and object have to exist. Fetishism, the metonymy of castrated penis, is also one of the factors to produce eroticism. Metaphorically seen as a woman who has a penis, a man who dresses in the same manner as a woman dresses can be a source of eroticism to gays. From a sociological view, the context in which eroticism is fostered depends on the dynamic relations among social powers. In these relations, who is a subject or who is an object has been continuously changing. In the Post-modern culture appearing in the late 20th century, power begins to take various forms, and gays and women who had never been subjects begin to make man an object of eroticism. The other point is that social morality, ignoring desire itself, objectifies sexual desire and seeks to remove It by exchanging it for objectified symbols. The design elements provoking eroticism in men s fashion are exposure and decoration. In particular, models in exposure and decorative fashion have been objectified through the methods of fragmentation rather than showing the whole figure or removing a person s individuality or will,.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.781-787
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• 1997

In spite of the improvements of the techniques in the field of preventive dentistry, many children still present with extensive destruction of primary anterior teeth. Not only the practioner must consider the pulp state of the primary incisor, but also restore the form, function and esthetics of the tooth. Restorative treatment of primary incisor tooth requires durability, retention and esthetics. Stainless steel crowns used in restoring primary anterior teeth is retentive and durable in comparison with the composite resin, celluloid crown. But they are not esthetic. To enhance the esthetics of the anterior stainless steel crown without reducing its superior retention, an open-face stainless steel crown has been suggested. Several authors have suggested cutting away the labial portion of the stainless steel crown and placing the composite resin in that area. By following this technique, the practioner can prepare a retentive, durable, and esthetic restoration for primary teeth which have suffered from extensive loss of teeth structure. In addition, the single missing primary anterior teeth can be successfully restored by soldering the stainless steel crown together. Open-face stainless steel crown is indicated in the areas of large interproximal lesions involving incisal edge, crown fracture with pulp exposure and congenital malformation of the teeth. By this technique, the practioner can restore primary anterior teeth successfully regardless of the amount of remaining tooth structure, bruxism habit and presence of attrition. In this case, rampant caries with extensive loss of tooth structure and single missing of primary anterior tooth hart been successfully treated with open-face stainless steel crown.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.357-363
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• 2015

The purpose of this study was to compare the inhibitory effect of bevacizumab on human Tenon's fibroblasts (HTFs) cultured from primary and recurrent pterygium. Cultured HTFs were exposed to 2.0, 5.0, 7.5, and 15.0 mg/mL concentration of bevacizumab for 24 hours. The 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase leakage assays were then performed to assess fibroblast metabolism and viability. The matrix metalloproteinase (MMP), procollagen type I C terminal propeptide (PIP), and laminin immunoassays were performed to examine extracellular matrix production. Changes in cellular morphology were examined by phase-contrast and transmission electron microscopy. Both metabolic activity and viability of primary and recurrent pterygium HTFs were inhibited by bevacizumab in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. Both types of HTFs had significant decreases in MMP-1, PIP, and laminin levels. Distinctly, the inhibitory effect of bevacizumab on MMP-1 level related with collagenase in primary pterygium HTFs was significantly higher than that of recurrent pterygium. Significant changes in cellular density and morphology both occurred at bevacizumab concentrations greater than 7.5 mg/mL. Only primary pterygium HTFs had a reduction in cellular density at a bevacizumab concentration of 5.0 mg/mL. Bevacizumab inhibits primary and recurrent pterygium HTFs in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. As the primary HTFs produces larger amounts of MMP-1 compared to recurrent HTFs, significant reduction in MMP-1 level in primary pterygium HTFs after exposure to bevacizumab is likely to be related to the faster cellular density changes in primary pterygium HTFs.

• Fisheries and Aquatic Sciences
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• v.6 no.2
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• pp.81-87
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• 2003

Experiments were carried out to investigate the accumulation and the histopathological changes in liver of juvenile rockfish, S. schlegeli, after sub-chronic dietary Cu (0, 50, 125, 250 and 500mg/kg) exposure for 60 days. Cu accumulation in liver was significantly increased with dietary exposure period and concentration for 60 days, and has a linear relation with dietary exposure days. After 60 days of Cu dietary exposure, the Cu concentration in the liver was $75.9\pm12.05,\;126.29\pm22.11\;and\;360.44\pm45.26\;{\mu}g/g$ dry weight and was approximately 11-fold, 18-fold and 51-fold higher than in the control diet group at 125, 250 and 500 mg/kg Cu diet group. The accumulation factors were increased with the dietary exposure period in liver of rockfish. In the primary exposed stage, the effect of hepatic tissue in the rockfish exposed to dietary Cu observed enlargement of hepatocytes nuclei, activity of hepatic cells and the swelling of hepatic cells. While exposed time and concentration were increased, the distinct granulation, irregular shape and necrosis of hepatic cells were observed. It was observed that granule degeneration and necrosis showed a part of cells in hepatic tissue after 60 days at 500 mg/kg.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.139-145
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• 2016

Environmental tobacco smoke (ETS) is a major public health problem for all ages. Despite the high prevalence of smoking among the Saudi population, there is limited information about levels of urinary cotinine in Saudi children exposed to SHS. The aim of the study was to assess the exposure of schoolchildren to ETS, and measure their urinary cotinine levels. Multistage cluster sampling was carried out, where schoolchildren from 4 schools were randomly chosen from primary schools in Taif city. A questionnaire including questions on SHS exposure and smoking rules in the residence were sent to students parents/guardians. Urine samples were taken and analyzed for total cotinine using chemiluminescent immunoassay. Of the studied children, 38.4% had a smoking father, 61.8%, 41.2% and 49.3% of them were exposed to ETS indoors, outdoors and both indoors and outdoors respectively. The mean urinary cotinine was significantly higher among children exposed to ETS compared to unexposed children. Urinary cotinine levels in children with both indoor and outdoor exposure was significantly higher compared with its level in children with single exposure. A significant positive correlation was found between urinary cotinine concentrations and the number of cigarette packs smoked by parents, and the number of smokers in the residence. The mean urinary cotinine level was significantly higher in children who reported no smoking rules at the residence.. The study revealed a high exposure of Saudi children to ETS. An antismoking media awareness campaign on the harmful effects of ETS should be carried out, in addition to family counseling programs targeted to parents to protect their children from ETS.